Ordnance sighting apparatus.



-33*235 DR 193009353 5R A. T. mwsow 6; G. 1-. BUCKHAM. ORDNANCE SIGHTINGAPPARATUS- APPLICATION FILED JUNE 2141917.

1,300,353. Patented Apr. 15,1919.

UNITED STATES PATENT OFFICE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUOKHAM, OF WESTMINSTER, LONDON,ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER,

ENGLAND.

Application filed June 21, 1917.

To all whom it may concern:

Be it known that we, Sir ARTHUR TREVOR DAWSON, knight, and GEORGE THOMASBUCK- HAM, both subjects of the King of Great Britain, residing atVickers House, Broadway, Westminster, in the county of London, England,have invented certain new and useful Improvements in or Relating toOrdnance Sighting Apparatus, of which the following is a specification.

This invention relates to sighting apparatus of the cam elevated typeand in which the elevating cam is situated at a substantial distancefrom the axis of elevation of the sight bracket. The invention is thusparticularly applicable to sighting apparatus for use in connection withcasemate gun mountings in which the range dial, arranged concentric withthe elevating cam, is situated near the rear end of the casemate shieldand the sight bracket is situated contiguous to the gun trunnions, thecam operating upon an extension or range arm rigid with the sightbracket. In such an arrangement the size of an elevating cam capable ofgiving the usual maximum range adjustment to the sight bracket isconsiderable; when therefore it is desired with this arrangement toimpart large range adjustment (for example practically double the usualadjustment) the size of the elevating cam, when a single cam isemployed, would become prohibitive; the chief object of the present invention is to avoid this difiiculty.

According to the invention the cam instead of operating directly uponthe range arm operates thereon through the intermediary of alongitudinally movable barv or similar member which is pivotally orsimilarly connected to the range arm at a point whose distance from theaxis of elevation of the sight bracket is as small as is practicable; inthis manner it becomes possible to impart the aforesaid large range adjustments to the sight bracket by means of a cam no larger than that atpresent employed for imparting the usual range adjustments.

In order that the said invention may be clearly understood and readilycarried into effect we will describe the same more fully Specificationof Letters Patent.

ORDNANCE SIGHTING APPARATUS.

Patented Apr. 15, 1919.

Serial No. 176,111.

with reference to the accompanying drawings, in which Figure 1 is a sideelevation and Fig. 2 a plan showing sighting apparatus constructed inaccordance with our invention.

Fig. 3 is a horizontal section drawn on a larger scale takenapproximately on the line a: w of Fig. l.

A is the sight bracket which is pivoted concentrically or approximatelyconcentrically with the gun trunnions and A is the sight carrier. A isthe range arm which is upwardly and rearwardly inclined and which isconnected by a transverse frame or bar A to a similar range arm situatedat the opposite side of the mounting. B is the elevating cam whichoperates upon the range arm A through the intermediary of the bar C.

In the example shown the bar C is pivoted at c to the range arm A of thesight bracket, the distance of the point a from the axis of elevation ofthe sight bracket being made as small as is practicable so as not toincrease unnecessarily the size of the cam B. The rear end of the bar Cis forked to receive a block 0 which is capable of sliding in a guide orbracket B attached to the gun cradle and supporting the cam B and therange dial B The forked end of the bar C is connected to the block 0 bymeans of a screw 0 the ends pf which are cylindrical to form a pivotalconnection for the said forked end of the bar. This screw also carries aroller C bearing against the cam B under the influence of a spring I;which surrounds the forward part of a sliding rod 6 connected with thesaid block 0'. This part of the rod is contained within a casing havinghollow nuts 6 b at its ends through whichthe rod extends and can slide.One end of the spring bears against the nut b and the other end againsta collar 6 on the said rod, which collar bears against the nut b forrestricting the rearward movement of the rod. When the cam B is actuatedto increase the range setting of the sight the roller C the block 0 andthe pivot screw 0 move in a rectilinear path along the guide B againstthe resistance of the spring I) and at the same time transmit forwardmovement to the bar C for operating the range arm A the ends of the barC turning about the pivot screw 0 and the pivot 0 respectively.

What We claim and desire to secure by Letters Patent of the UnitedStates is I. In ordnance sighting apparatus, the combination with thesight bracket, of a cam, a longitudinally movable member interposedbetween the cam and the sight bracket, means for guiding said member,and a common support for said elements.

2. In ordnance sighting apparatus, the combination with the sightbracket, of a cam, a longitudinally movable member operated upon by thecam and pivoted to the sight bracket, means for guiding said mem her,and a common support for said elements.

3. In ordnance sighting apparatus, the

combination with a gun cradle and the sight bracket pivoted to the guncradle, of a cam mounted on the gun cradle, a longitudinally movablemember operated upon by the cam and pivoted to the sight' bracket, andmeans carried by the gun cradle for guiding said member.

4. In ordnance sighting apparatus, the combination with a gun cradle andthe sight bracket pivoted to the gun cradle, of an arm on said bracket,a cam mounted on the gun cradle, a longitudinally movable bar operatedupon by the cam and pivoted to said arm and means carried by the guncradle for guiding said bar.

In testimony whereof we affix our signatures.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. 0."

